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A small electric flash evaporator to dewater WVO.
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PerkHouse -- Multiple small orifices -- OK, all from one heat source. The multiple small orifices may not actually be nescicary, I just have not done any testing of using a larger single oriface yet. I suspect that several smaller orifici (?) would dewater better than one large one due to better microbubble bursting but I can't say for sure until I test this, not happening any time soon as I don't need to dewater any faster than my current 5 G/H (may increase this to 10 G/H just to test, it can be done faily easily with my current setup by increasing the orifice diameter and cranking up the heat)

Multiple heaters -VS- one big heater -- I don't know how well one large heater will do with a high flowrate, may overheat the oil that is in direct contact with the heater into cruspyness, or it may not have enough time to thoroughly heat all the oil passing through the chamber or it may work just fine ? I had considered making a heat chamber from say - 2 inch pipe- with a bell reducer on the end for the heater element rather than the 1 inch pipe that I am now using. This 2 inch heat chamber would have 4 times the area so the flow through the chamber would take 4 times as long, don't know if this is better or not ?. This is another area that will take some experimenting to find out.

I have done some testing concerning "watt density" of heating elements and find 250 watts of heat from the normal cheap 4500 watt heater element is a low enough heat/area that STATIC oil is not burnt or crispified. From using the FE as now configured it looks like 1100 watts of heat is about the limit for my 5G/H flow rate as I am creating just a few "bits" that require a filter. It will be interesting to see your results of using one 4500 watt heater element (an assumption, just what will you start testing with) with a flowrate of 15-20 G/H. The "watt-density" discussion is here.

Bash plate distance -- I have not done much testing concerning this, It just turned out that 4 inches was what looked about right for the small flash tank that I am using, glad to hear it is about optimum.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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I stumbled on a ready-made orifice with built-in bash plate: a room fire protection sprinkler nozzle, available in a variety of designer materials including stainless steel.
Cheers,
JohnO
 
Location: Moses Lake, WA, USA | Registered: August 15, 2001Reply With QuoteReport This Post
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Johno,
All the fire sprinklers I've looked at have an orifice size about the size of the pipe fitting. A 1/2" orifice is about 27 times too big for this application. Have you found one with an orifice size around .018"?

However, you may have something with the fin type splash plate. I suspect it would help vaporize the water, but I wonder if it would also vaporize more oil.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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I hadn't looked closely at the orifice. They're listed as being bushed, so it would be easy to make a custom insert to reduce the diameter. They list them by K-coefficient, not my diameter, so I had to do some digging:

Q=KP^1/2
Q = gallons per minute flow.
P = pressure in PSI.
^1/2 means take the square root of the pressure.
The smallest coefficient listed by Viking is 2.8, which gives a water flow of 14gpm at 25psi. Sorry to mislead. The concept of the finned/interrupted splash plate might be useful - they're designed that way to give predictable droplet size and distribution, which are things we like. To properly penetrate a fire though, large droplets are needed, the opposite of what we want. Large droplets have less surface area than an equal mass of small droplets, and surface area is necessary to evaporate stuff quickly.
Cheers,
JohnO
 
Location: Moses Lake, WA, USA | Registered: August 15, 2001Reply With QuoteReport This Post
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The flash evaporator seems too complex for me. Has anyone tried mixing a drying agent in the oil to absorb it and then just filter it out?
 
Registered: May 19, 2006Reply With QuoteReport This Post
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brain,
There are many threads on other methods of removing moisture (dessicants, molecular sieves, kitty litter, etc, etc, etc). Just do a search and you should find hours of reading enjoyment/torture.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post



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Tim Cook expressed some concern for brass orifices. McMaster-Carr has Stainless, but they take 2 weeks to order. This may have been handled in some other part of the tread, but I thought I would give the part number.

http://www.mcmaster.com/nav/enter.asp?partnum=2712T578&pagenum=445

Brass 2712T49 $8.63
SS 2822T19 $17.93

Building my own flash evap with a friend whose own system works well. Mine will use multiple nozzles (we hope). Will post results.


Mike Goodman
High Point, NC

83 MB 300SD (2 tank) - Greasel
98 Dodge 2500 (2 tank) - Golden Fuels
82 Rabbit Truck (2 tank) - my design) - SOLD
Diesel Craft CF process in enclosed shed
BD first batch 9/23/12, still going ..
6-4x10 solar hot water panels and 500 gallon wood-burning water stove
2.8 kW PV grid-tie w/batt b/u commissioned March 2011
 
Location: High Point, NC | Registered: September 30, 2005Reply With QuoteReport This Post
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The Suntec pumps Mike and I bought have a return port and when using it on a single line system (like we are), the user is just supposed to leave that port plugged as it is. But, if using a return-to-tank line, there's a little plug that goes inside. Well, dummy me, I got confused and installed the little plug and that's when the shaft seal blew.

The good news is that I PM'd Tim and did just as he suggested in disassembling the unit. As soon as I removed the shaft the seal returned to its normal shape, so I put it all back together and it ran fine after that. We got 140 psi out of the box with no adjustment running 2 .016" orifices. We tried 4 orifices, but Tim was right: the heating element just couldn't keep up, but it cycles at about 50% duty cycle (Watlow PID temp controller) with 2 orifices.

The motor we're using right now is just an old piece of junk that I pulled from an ancient Eureka canister vacuum. I have no idea what it's RPMs are, but by the sound of it, it's fast, but not as fast as my 5000 RPM circular saw motor.

Right now, we're using a piece of 1/4" fuel hose for a shaft coupler, but I found some good couplers at McMaster-Carr at less that $6 for the set. The part number is 6408K11
They'll run up to 18,000 RPMs @ 23 in-lbs of torque. The online calculator I used said that 1/3 HP @ 3450 RPMs is only 6 in-lbs of torque. So, these should be fine.

The pump runs pretty hot. I'm wondering if we use the return port to send the excess fluid back to the tank if the pump will run cooler. Any ideas?


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Tim,
You had mentioned that you know how to mod the Suntec pumps to run at lower-than-rated RPMs. Can you tell me how to do that now?

Mike and I got some 1100 RPM 1/6 HP motors today and I haven't actually tried it yet, but I doubt they'll get the pressure up on a 3450 RPM pump, but would like to try them out.

Thanks!


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Suntec pump mods eliminating RPM deturmined flowrate control --

I have only done this on the "A" style pump and am working from memory until I find the parts that I removed from the pump..

Once you remove the 4 bolts in the corners of the aluminum pump cover, remove the cover, this uncovers the internal screen that is held in place by the cover, remove the screen. In the center of the pump is a stack of what look like 1 3/8 inch round 1/4 inch thick metal plates held together with 3 small bolts, removing the bolts allows you to un-stack these. The top plate has a large cavity on it's underside, there is a large diameter spring in this cavity, between this top plate and the second plate is a thin diaphragm, this diaphragm has spring pressure on one side and oil pressure on the other, There are oil passages in the outer plate that allow oil from the pump to recirculate through these passages until there is enough flow to increase the pressure on the innermost side of the diaphragm so that it flexes outwards against the pressure of the spring, once the diaphragm flexes outwardly enough it closes off the center passage inside the outer plate, the instant this happens the oil pressure jumps up dramatically and causes the pressure regulating spring-loaded plunger (under the oil outlet fitting) to be pushed back inside it's passageway until the oil pressure pushes it far enough into the passageway to uncover another bypass hole, the adjustable pressure on the spring behind this plunger is what sets the max pump pressure (only have max pressure if the flow out of the pump is restricted to some smaller-than-max flowrate)

OK -- The idea is to use some method to permanently block off the internal flow passages rather than waiting for the diaphragm to do it. You can thread one of the passages in the outer plate and screw in a setscrew, this would allow you to return the pump to normal at a later date -or- you could drive a BB (or some other plug) into a passage, or probably fill a passage with JB weld or some other epoxy. I chose to make a new outer plate with no passages in it from 1/4 inch thick aluminum plate. This allow me to return the pump to it's original condition in the future.

I traced the round shape of the outer plate on the aluminum, located the center of the 3 mounting holes with a punch, roughed the plate sort of round using my table saw with a carbide toothed blade, used a belt sander to finish making the plate mostly round, drilled the 3 holes. I removed the thin diaphragm and it's big spring and mounted the new blank plate in place of the original plate with the cavity. No gasket needed between the plates if you sand the inner surface of the new plate flat using the belt sander, and tiny amount of oil that may leak from between the plates just ends up being recirculated through the pump gears again although excess leakage will limit the upper pressure capability of the pump.

Almost easier to do this mod than to explain it.

The pressure regulating plunger on most of these pumps has a bit of machining done (flats) that allows it to also bypass some oil until there is more oil than it can bypass, then it pushes back and starts regulating the pressure. To get the plunger to push back the first time I ran the pump slow I had to smack the side of the pump with a wrench and make some vibrations, this caused the pressure plunger to shift and the output pressure jumped from 40 pounds to 150 pounds. I only had to do this a couple of times, I think once the pump had cold veg in it the oil was too thick to bypass so the plunger shifted as soon as any pressure was created.

Leave the screen out of the pump when you assemble it, the mesh of the screen is what controls the stated 3 G/M flowrate of these pumps and that is based on much thinner #2 HHO (diesel). Found a referance to 17 G/H being the max for my "A" pump at 3600 RPM.

The actual pump gears are under the second plate in the internal stack, lifting this plate will let you see the pump gears and the method that it uses to move the oil. As long as the oil you feed the pump is filtered smaller than the spaces in the pump gear teeth you should not have a problem of the pump jambing internally from bits of stuff in the oil.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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PerkHouse -- How are the two seperate gear sets of the "B" style pump arranged, I suspect they are in a couple of layers of the internal plate stack, the single gearset of the "A" pump has 3 layers, does the "B" pump have 4 layers?
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Ok... I finally got back to my FE project today.

Tim, the B version actually has 5 layers, unless you weren't counting the back plate in the stack. In that case, yes it has 4 layers.

Mike and I went to the salvage yard the other day and scored a bunch of good stuff for $20. (I didn't have any cash on me. Thanks again Mike!) In the lot, we picked up 2 motors: 1100 rpm @ 1/6 HP (110V only, but reversible).

I modified my Suntec pump to run at less-than-rated speed, but I found a simpler solution than fabricating a new back plate. Of course, I removed that (silicone?) "diaphragm" and the spring, but I didn't replace the back plate. Instead, I just cut out a circle from a smooth piece of HDPE (#2) plastic and put that in place of the spring and the diaphragm. I cut my plastic circle about 1/8" bigger than the aluminum circles.

Then I cranked it up, but I couldn't get anything out. I tried rapping it with a hammer and still nothing. Since I'm not using the "Return" line, I realized I needed to bleed the air out. As soon as I did, the pump sprang to life and I immediately had 90 psi. I just fiddled with the pressure screw and before I knew it, I had 150 psi. I didn't try going any higher because I had some minor leaks and I've been dewatering (effectively) at 100 psi anyway.

On the negative side... both of my ShurFlo pumps died today. And both quit working shortly after pumping a blend of 60/40 kerosene/gasoline. I can't be absolutely sure, but I think I've pumped that blend before without problems. OTOH, it might have only been kerosene that I pumped in the past. Could the gasoline have destroyed something?

I opened up the newer (higher capacity) pump and the center diaphragm (it has a total of 4) looked somewhat deformed. I tried to open the smaller pump (like Tim's), but one of the screws wouldn't budge.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post



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Replacing the diaphragm sounds like the easiest way to eliminate the RPM restriction, I just did not think of it. Just don't drill the holes for the in/out flow passages to the top plate.

Shurflo and gasoline -- Never tried it but it may be the problem, don't know how the plastic diaphragms would react to it. There are a couple of different type plastic innerds available for these but I don't know if any of them will withstand gasoline.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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(My plastic gasket just has the 3 mounting holes.)

Can I order replacement Shurflo parts?

Oh and I forgot to mention... the pump is running much cooler now. I suspect that running at the much lower rpms has significantly reduced the internal friction of the higher viscosity fluid and the gears, shaft seal, etc.

By the way, I talked to an Engineer at Suntec who told me that he used to pump acid (didn't say what kind) with these pumps. He said his procedure was like this:

1. Drain motor oil out of pump
2. Pump acid for hours
3. Pump water to flush/neutralize
4. Pump K1 to remove water
5. Fill with 30w motor oil for storage

When I was finished dewatering yesterday, I turned off the heating element and ran about a qt of K1 through it to help cool it down and to pre-clean my filter and orifice.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Here's the diaphragm.



Warning: do NOT try to pump gasoline - even diluted - with a ShurFlo pump.


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Well -- Does not look like you will get much valve action out of that plastic valve. Yes, parts are available, a quick web search should find several retailers, they also are available on ebay occasionally for about half the retail cost.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
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Tim, everyone, can't say enough on your efforts with this FE topic. Hope to get there one day.

Here are a few thoughts:
1 Using fuel hose as a coupler -- awesome (that gets me thinking) for larger shafts, you might consider the old steering wheel knuckle coupling that uses a rubber disk, solves a lot of alignment problems.

2 I have access to orifice calculation software. To size your orifice the following will be needed: line I.D. flow rate, specific gravity, pressure drop. Would like to help if y'all want to get a gnats arse figure.

3 Someone asked what PID stood for: Proportional- Integral- Derivative control. Full explanation gets into math and all, but the important thing to remember is that there is a "gain" value which applies to each of these terms. The gain values are adjustments you make when you configure your controller's parameters. I would suggest staying away from using Derivative control. This generally causes instability and large swings in your output. The integral term generally guarantees that you control at set point. Proportional (kind of like adjusting the volume on your stereo) only might get you control, but you would be a few degrees off. If anyone is using a PID and the output swings erratically, or it take a long time to get to setpoint or the controller handles swings poorly, then the tuning probably needs adjusted. I have info on how to do this, not electronic (yet?) however.

4 Not sure if anyone was doing this but you can control the pressure as well as temperature with PID controllers.

5 An orifice can be made by drilling the smallest hole you can in a pipe cap. Of course this whole will be way to big, but you can beat the cap to close it up. It will take some playing around.

6 No one has mentioned using a similar rig to dry finished biodiesel. Is there some reason why this would be a bad idea?
 
Location: SE Louisiana | Registered: July 19, 2006Reply With QuoteReport This Post
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parts are often available at farm supply stores
 
Registered: July 04, 2006Reply With QuoteReport This Post



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EsterBunny:

Both SWMSGoodman (aka Mike) and I are using PIDs to control our temperature, but we are seeing extremely stable temperatures at the output of our heating chambers, within +/- 2C. Of course, we could probably fine tune that to get the temp even more stable, but I doubt we'll bother. If it's fluctuating +/- 10C, it's still going to be close enough.

I've often thought about your comment #6 too. Of course, I don't make biodiesel anymore, but if I did, I'd probably try this (with a lower pressure and at a lower temp).


Brian

2000 Jetta TDI
1982 Mercedes 300D Turbo
1986 Isuzu P'up (NA)
1985 Mercedes 300D Turbo
75/25 WVO/D2 for warm weather
50/50 WVO/D2 for cold weather
Uniqueness is a treasure not to be buried. - Laurence Martel
 
Location: High Point, NC | Registered: May 04, 2006Reply With QuoteReport This Post
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Funny, It never dawned on me that this thread was for SVO
 
Location: SE Louisiana | Registered: July 19, 2006Reply With QuoteReport This Post
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